Changes in the heritable attributes of populations of organisms over time. The mechanisms of evolution are mutation, migration, drift, and selection.

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How does discontinuous distribution provide evidence for evolution?

One of the evidences for evolution is bio-geographical evidence. In it,'discontinuous distribution' is mostly cited as an evidence. For example, Alligators are found only in south-eastern US & ...
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Are there examples of selection on males influencing female phenotypes?

I've been studying selection on female body color in a sexually dimorphic species and am intrigued by the possibility that selection on males, whether it be through sexual or natural selection, may ...
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80 views

Why does the Vas Deferens detour over the pubic bone?

I was surprised to learn that the vas deferens detours over the pubic bone instead of taking the obviously more direct path. https://human.biodigital.com/widget?be=u1P&uaid=1ly5V Because I would ...
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2answers
199 views

What does 'direction' mean in the statement “mutations are non-directional”?

I was reading the Mutation theory of De Vries; there I encountered this following statement: Mutations are discontinuous, random & non-directional.This is in contrast to Darwinism where ...
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610 views

Why are eggs “egg” shaped?

Is there a reason as to why chickens lay "egg" shaped eggs, as opposed to spherically shaped eggs (or a random shape)? <--- Main Question For extra points (actually just to add more words in ...
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901 views

What is the evolutionary explanation for bat's echolocation [closed]

The bat's ability for echolocation is amazing (so are other the abilities of other animals). I was wondering how all of it came to be.
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49 views

Why are there different species of bacteria?

The usual (high school or intro to bio) explanation for diversification of species comes from multicellular, usually sexually reproducing organisms, and seems to be closely tied to the biological ...
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53 views

How did dolpins acquire the dorsal fin?

I had been thinking bout atavism when I saw a picture of a dolphin. I had seen it before, but suddenly the dorsal fin startled me. How did this dorsal fin evolve, especially, is it some atavism from ...
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97 views

What's the mechanism or structure responsible for new species genetic code generation? [closed]

I always had this question in mind. I think, If humans find answer to it then we can trigger the next evolution of human specie. What is the mechanism or structure responsible for evolution ? I don't ...
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Why plants and animals are so different even though they come from the same ancestors?

All the documentaries I have watched, books I have read so far on the starting of life on earth only talk about animals. The very first life form on earth was bacteria. Then evolution took us this ...
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105 views

Are human beings evolved to eat meat? [duplicate]

I know humans can cook, and prepare almost anything, but are humans specifically adapted to eat meat. One of my doubts humans are not particularly well adapted to eat meat because they lack canine ...
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91 views

Escaping resource limitations during tumor evolution

In their discussion of the importance of r- and K-selection on tumors, Aktipis et al. (2013; figure 3) provide the following illustration of a hypothetical cancer growth curve: In it, you can see ...
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110 views

Why did multicellular organisms evolve when a single cell can survive on its own? [duplicate]

Since unicellular organisms can survive, why would there be evolution of multicellular organisms?
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Crossing over and exon shuffling?

Campbell Biology 10e, in discussing the functions of introns, writes: The presence of introns in a gene may facilitate the evolution of new and potentially beneficial proteins as a result of a ...
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53 views

Why did eukaryotic cells develop? [closed]

If eukaryotic cells can survive in extreme conditions, then why are their still prokaryotic organisms?
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55 views

Do animals demonstrate target practice (i.e., playful accuracy behavior)?

Do animals demonstrate any sort of accuracy-motivated play? (please provide examples!) Consider most human sports and related hobbies. Most share the common goal of hitting a target or being ...
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5answers
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Why are there species instead of a continuum of various animals?

As I understand it, various animal traits have to evolve gradually, but what happens to the species that are "neither here nor there"? To put it differently, if a species evolved from another, it did ...
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75 views

Evolution of dominance of alleles

Can someone tell me where can I find detailed text about mechanisms of evolution of dominance? Or, if it is possible, I would be grateful if someone will tell me about them here.
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146 views

The replicator equation vs the Lotka-Volterra equation

Background The replicator equation with $n$ strategies is given by the differential equation: \begin{equation} \dot x_{i} = x_{i} \left( \sum_{j=1}^{n} a_{ij}x_{j} - \phi \right) \qquad i = 1, ...
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38 views

Does the bending of a tree's trunk in the wind stimulate and strengthen root growth?

Recently Southern California experienced extreme wind velocities and afterwards the news reported over 300 trees had fallen in San Diego County. I had either heard or read somewhere that the action of ...
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87 views

What came first? The DNA or the DNA polymerases?

I know this sounds a lot like chicken and egg question and while the latter has an answer, I am intrigued about the former. A modified form of the question would be, in the course of abiogenesis, ...
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372 views

Examples of animals with 12-28 legs?

Many commonly known animals' limbs usually number between 0 and 10. For example, a non-exhaustive list: snakes have 0 Members of Bipedidae have 2 legs. Birds and humans have 2 legs (but 4 limbs) ...
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44 views

Is it known how human sweat glands evolved?

If human descends from apes than probably we lost our hair. Perhaps in the age of homo erectus we lost our hairs and began transpiring through our skin with sweat glands. But how did these glands ...
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3answers
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Why do our eyes close when we sleep?

Why do our eyes close when we sleep? Is it to relax our eye muscles? How can it be explained from an evolutionary point of view?
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83 views

Evidence of species transitions [closed]

I had a debate with a person who believes in some kind of creativism, let's call it that way. And in the middle of the "debate", an interesting question popped up. What are evidences of ...
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Was the frequency of mutations more during primitive earth due to radioactivity?

Primitive earth was more radioactive (or was it really?) according to radiometric analysis of C14 which suddenly appeared at 4250 million years in the Hadeon eon. Is it possible that ancient high ...
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Why does the proportion of transposable elements vary so much across species?

Intuitively, transposable elements (TEs) are harmful as they may cause genome instability. However, some people argue that TEs are also sources of variations, especially regulatory sequences[1]. If ...
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The evolution of sleep [duplicate]

Are there evolutionary theories as to why we (and most animals) sleep? Some claimed functions of sleep include: restoration, waste clearance, memory processing, etc. But unless we understand why ...
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72 views

Why doesn't lard taste good? [closed]

I mean looking from evolutionary perspective sugar tastes sweet and individuals that had this perception ate more sugar and survived and those that didn't perceive sugar as sweet didn't eat it and ...
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3answers
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Why did abiogenesis only happen once?

If the "primordial soup" theory of abiogenesis is to be believed, self-reproducing organisms spontaneously arose on Earth at least 3.5 billion years ago, surprisingly soon after the Earth cooled down ...
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Why are the Galápagos islands so special?

Why did Darwin formulate his theory of evolution just after his visit to the Galápagos islands? Why were they so special from an evolutionary point of view?
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131 views

Have scientists ever produce a new species in laboratory by means of natural selection?

I was wondering, if scientists ever produce a more complex species from a less complex species by means of natural selection? I imagine something like, bacteria which can't photosynthesis and oxygen ...
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147 views

Can someone help me analyze this article? [closed]

I need to read this article — "Beyond the rainbow" by Marie-Claire Koschowitz et al., for an exam. Following are some questions for which I could not figure the answer out after reading. 1) Why ...
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1answer
58 views

How to understand Aposematism and Batesian mimicry

EDIT I want to understand the reason for intense animal colors. I.e. I don't want to understand the variety of the colors, just the intensity. The Wikipedia page for Cethosia biblis says, the intense ...
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76 views

Does evolution thinks? [closed]

I understand evolution as survival of the fittest rule , where its the nature and surroundings that shapes the life by extinction of species which are not fit to survive the nature at that period. To ...
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206 views

What is most ancestral: isogamy or anisogamy?

Sexual reproduction can be feasible with anisogamy (gametes of different sizes i.e. genders) or isogamy (gametes of same size i.e. mating types) or with undifferentiated gametes (i.e. true random ...
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261 views

Why asexual reproduction?

When I took a course on genetics and evolution, I learned that recombination and sexual reproduction is advantageous compared to asexual reproduction. Sexual reproduction allows more combinations of ...
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235 views

Can diploidy evolve in absence of sexual reproduction?

Theoretical question Can diploidy (or polyploidy) evolve from a haploid lineage in the absence of sexual reproduction ? For what theoretical reason? How can such evolution take place? Empirical ...
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Why is marginal reconstruction “more correct” than joint reconstruction in some cases?

When reconstructing the ancestral states on a phylogenetic tree given the states at the tips, there are a number of methods for performing the reconstruction. This question is about marginal and joint ...
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Why even if all requirements for natural selection are met, it may not happen?

In the book written by John Endler Natural Selection in the Wild p. 4 it says that even if condition a, b and c are met, evolution by natural selection might occur, [...] , but not necessarily, ...
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185 views

What are the minimum conditions required for “open-ended evolution”?

According to a paper about artificial life systems, the following four conditions have to be fulfilled for "open-ended evolution": Condition 1: A rule should be enforced that individuals must ...
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2answers
2k views

Why do humans bury their dead? [closed]

As far as we know Ape Men or the Neanderthal Man was the first to bury its dead. My question is why. I don't think they practiced religion or believed in spirits or faith or stuff like that. ...
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Is an egg classified based on the species inside it, or by the species that laid it?

Basically what I'm asking is if an animal of species x were to lay an egg, and the animal inside that egg happened to be the first member of a genetically new ...
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85 views

Is there a formal definition of signature of natural selection?

I’ve searched for a definition of signature of natural selection. Unfortunately, I haven’t found any formal definition of it. The signature of positive selection ...
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274 views

Symmetry of species [duplicate]

I've got a silly question, sorry for that. I know, that we probably have no the right answer and the current answer could be "that's evolution, external conditions". I'd like to speculate, why most of ...
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2answers
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Evolution of spider webs?

Web making seems like a fairly complex behavior built from a pretty strong material. So how exactly did it evolve? Do we have any clues about what kind of features/behaviors preceded web making and ...
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1answer
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How does the value of K determine number of local optima in NK model?

BACKGROUND The NK model of fitness landscape considers N states which can interact with K other states. For example N is the total number of genes in a haploid genome and K is the number of other ...
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1answer
60 views

What makes animal to continually reproduce? [closed]

I was reading about Trypophobia and reached to Surinam Toad's reproduction methods. Then I had this doubt- Why would animals want to reproduce so much? In case of humans we mostly have the offsprings ...
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1answer
77 views

What are some useful (starter) metrics to use on phylogenetic trees?

Im doing a computational biology project in which I simulate evolution under different inheritance rulesets and I am generating phylogenetic trees (beautifully visualised in python with ete3, which I ...